The hadronic nucleus-nucleus cross section and the nucleon size

TL;DR

This paper investigates the impact of a smaller nucleon size on the hadronic nucleus-nucleus cross section and quark-gluon plasma properties, revealing improved agreement with experimental data and challenging existing estimates.

Contribution

It demonstrates that a nucleon width below 0.7 fm better explains recent LHC measurements and influences quark-gluon plasma characteristics.

Findings

Smaller nucleon width improves the description of triple-differential observables.

Measured cross section suggests nucleon width is below 0.7 fm.

Contradicts previous Bayesian estimates of nucleon size.

Abstract

Even though the total hadronic nucleus-nucleus cross section is among the most fundamental observables, it has only recently been measured precisely for lead-lead collisions at the LHC. This measurement implies the nucleon width should be below 0.7 fm, which is in contradiction with all known state-of-the-art Bayesian estimates. We study the implications of the smaller nucleon width on quark-gluon plasma properties such as the bulk viscosity. The smaller nucleon width dramatically improves the description of several triple-differential observables.